Genres like architectural photography, abstract photography, people and portraits , photos captured on the beach , forest or mountains, bus or railway stations, inside train or subways, are part of street photography for me.

Subway stories- Tokyo- Street Photography

Simply anything and everything that happens on the street or belongs to the street can become a subject for street photography. Once you leave your home and you are out, street becomes your playground. Obvious exceptions being point no.1, 2, and 3 described above, though roads or tracks may be part of that experience and can fall under category of street photography.